Definitely a step in the right direction but not knowing the provider of service would probably be the biggest reason for me not to subscribe. Also there are no guarantees that the service would remain available in the future. If I didn't keep track of my coins and your service shut down for whatever reason I'd be out of luck!!
Free, eh? What's the business model that will sustain maintenance and future development of this app? Ads?
It would be nice to have a comprehensive manager that allows you to customize, such as add varieties for series that may have 100+ varieties per date, and that allows you access via a mobile app so I don't have to lug around a laptop or pad to shops and shows.
It'd be set up strictly on a very transparent donation system. I'd keep a running total accessible on the site so people can see the investment compared to donations. Like I said in my first post, I'd be doing this primarily as a fun side project to benefit myself, but what I'm curious about is if there's enough interest in it within the community to justify building it out a bit more to make it useful for others. If it really takes off, sure, I might throw 1 tasteful and/or discreet ad slot on the site, but that will stay at a minimum (because I hate ads as much as the next guy, but they can be helpful and serve a purpose if implemented properly).
While an old thread, I hope my reply is ok. As a developer I ran into this very need. I had different items that I collected... some old comics from my high school days, some coins I was getting into collecting and some trading cards. I was using Excel, but wanted a way to have the data with me, including galleries - whenever I wanted. I came up with this collection management site: http://icollectr.com it fit my needs, but I'm open to adding features that other collectors might find useful. The site is free. Currently some of the features at www.iCollectr.com are: registration is free your data can be exported to CSV for excel import at any time you create your own collectible categories (i.e. Coins, World Coins, Silver Coins, Comics, Stamps...) Any item you add, with an image, will auto add the image to your own public gallery that you can share (an example gallery would be http://www.icollectr.com/gallery/demo which has a variety of different items in it... coins, stamps, comics... this of course is tailored to one's own personal collection.) Any item you add with a certification # from PCGS, NGC, IGC or CGC (cgc is for comics) will dynamically create a link/button to the public data on that item, with that authority There's a "market value" column that links to eBay for sold data for similar items. The grid/list of your items is sortable by the categories you create (i.e. World Coins vs US Coins, or Comics vs. Coins, etc.) I can't say it's the best, there is no doubt some great sites out there... it met my needs and I opened it up to the public through a registration system. Feel free to try it out or if you have input on what would be valuable to you as a collector, let me know and I'll see if I can add it into the site.